This invention relates to the printing of textile materials and, more particularly, to the printing of such materials utilizing foamed printing compositions.
In recent years the art of printing pre-selected patterns on textile materials has become increasingly developed and widespread. Typically, such processes utilize a printing composition which is applied to the engravings of a printing cylinder, which cylinder is then brought into contact with the textile to transfer the print composition thereto from the engravings. Alternatively, a printing composition may be admitted to a rotary screen printer wherein a print composition is forced through the stencil-like apertures of a surrounding printing cylinder in contact with the textile material.
The most recent advances in this environment center on the formulation of the print composition, particularly in the utilization of foamed printing composition. Thus, for example, U.S. Pat. No. 2,971,458 to Kumins, et al. describes a process for printing textile materials wherein a printing paste thickened by incorporation of air therein is used. More recently, our commonly-assigned co-pending U.S. patent application Ser. No. 584,389, filed June 6, 1975 now U.S. Pat. No. 4,118,526 describes processes and compositions for applying finishing agents, including colorants, to fabrics wherein the agent, liquid and a foaming agent or stabilizer are whipped into a stable foam having a specified range of density and blow ratio. The foam is applied to the fabric and then collapsed to achieve penetration of the finishing agent into the fabric.
The utilization of such foamed compositions has the advantage of significantly reducing the amount of liquid medium needed in the print composition as compared to conventional processes and thereby, among other advantages, reduces costly liquid removal processes and processing difficulties associated with the large liquid absorption capacity of many textiles.
In the printing of patterns on textiles utilizing foamed printing compositions, the foam is, of course, applied to only selected portions of the textile corresponding to the pre-selected engravings or stencils of the printing apparatus. It has been found that difficulties may be encountered in penetrating the fabric with the printing composition, particularly in the uniformity and extent of penetration of the print into the textile. Thus, for example, where foam collapse and penetration is to be achieved by application of a vacuum to the underside of the textile, it is found that the vacuum will pull or act primarily in those areas offering the least resistance, i.e., in the areas where foam has not been applied, resulting in non-uniform penetration of the print into the textile. Such may present a particular problem when printing on high pile fabrics.